The present invention relates to a muffler cooling structure for a liquid-cooled engine system mounted on, for example, motive working machines such as agricultural tractors or the like, generators and the like.
In an agricultural tractor having mounted thereon a liquid-cooled engine, an exhaust muffler is disposed on the outside of an engine compartment or housing in order to prevent a rise in temperature within the engine compartment. This necessitates provision of a strict or cumbersome protecting cover or the like to protect an operator from touching the exhaust muffler. Further, disposition of the exhaust muffler on the outside of the engine housing inevitably enlarges the overall external dimensions of the tractor.
In recent years, a system has been developed in which purging due to exhaust gas is utilized to cool the exhaust muffler disposed within the engine compartment. It is difficult for such system, however, to sufficiently cool the exhaust muffler.
As the prior art, there is Japanese Utility Model Application Laid-Open No. 61-136127.